Siblings with 4H leukodystrophy – A rare cause of hypomyelination

Abstract

A 35-year-old man presented with slowly progressive ataxia since childhood, failure of development of secondary sexual characteristics, primary infertility, delayed dentition, and moderate sensorineural hearing loss on both sides. On physical examination, there were unerupted first molar teeth on both sides, lack of axillary and facial hair and a small-sized penis. He underwent a magnetic resonance imaging (MRI) examination of the brain which showed diffuse hypomyelination with relative sparing of bilateral posterior limbs of the internal capsule, the ventrolateral nucleus of the thalamus, and optic radiations, along with a hypoplastic anterior pituitary gland. Hence, 4H leukodystrophy was suggested radiologically which made us curious to ask for family history which revealed similar symptoms (absence of secondary sexual characters) in his younger male sibling. MRI brain screening was also performed for the sibling, which showed diffuse cerebral hypomyelination.